Balance-staff-pivot-truing device.



D. L. DAVIES. BALANCE STAFF PIVOT TRUING DEVICE.y

' APPLIUATION HLED JULY 1, 1907.

v9,3429I Patented sepnmfwo? ('llito'amatagly I DENNIS ILYIDAVIES, OF' NELSON, NEBRASKA.

i BALANCE-STAFF-PIYOTLTRU'ING DEVICE.

Specification of Letters Izitent.l Patented Sepivl, 1909.

Application flied July 1, 1 967. Serial No. 381.789.

To all 'whom 'it may concern:

Be it known that l, llnNNis L. DAvms, a citizen of the United States, residing at. Nelson, in the county of Nnck'olls und State of Nebraska. have invented a now and useful Balauce-Stuif-Pivot-Trning,Device for Jewelers Lathes, of which the following is a specification.

'lliis invention relates to watchmakers` tools and especially for a device for truing the bent pivot of a balance. stati of a watch, and has for-itsobject to provide a simple, inexpensive and efficient. device capable of receiving the bent pivot of a balance stati' which is to be straightened.

The invention consists in the novel features of coiistructioffiivhich hereinafter are fully descrilfiedl in the course of the following specification .with reference to the accompanyingv drawings and more artiularly pointed out and distinctly de ned in the claimshereto appended. f

Referring to the accompanying drawings forming a part of this specification wherein like .oharacters of-rgference denote similar parts tlfroughout thej, several.views: Figure l, is as elevation on a jeweersriathe having my'invention applied thereto. F ig. 2, is a vertical sectional lView on line w-w of Fig. 1, looking in direction of the arrow and clearly showing the steel taper as in actual use in straightening the bent pivoty of a balance staff. F i0. 3, 1s -a central sectional view of the truing device. Fig. 4 isa perspective view of the-truin r device. Fig. 5 is a perspective View of t ie steel taperused in 'connection with thc truing device.

vReferring to the accompanyingi drawings 1, designates the bed ,of a jewelers lathe, 2, Ihead-stockprifyvided with the spindle 3, inv

the end offr'vhich vis held a wirechuck 4. The

lathe is also provided with the tail-stock spindle (l, which in turn receives and `firmly holds the tI-ning device in a stationary position.

Thetruing device 7 which is turned from a piece of steel or other suitable material has a cut-away top portion 8,*and a projecting front or head 9, circular in form and which is provided 'at its center with the conical opening 10, adapted to receive the pivot 11,

portion to form a convexe 'plate and a circular pro]ect1ng front pro vldedwith a conical opening to receive the of a balance stati' 12, as clearly shown in Fig. 1. The bed 13, of the truing device 7, it

will be observed is convexed as shown and the highest surface of the bed 1s far enough below the opening 10, to allow `the insertion ot the steeltaper 14, between the pivot 1.0,

and convexed bed 13, as clearly shown iu Fig. 2. By gradually crowding the steel taper 14, forward it will be readily seen that when the balance staff is revolving the bent slightly upward, downward or straight forward.

Tn operation the balance stati' is firmly held 1n place by means of the revolviiig wire .chuck 4, clearly shown vin Fig. l. A cylindrical end 15, of the truing device 7. is'

sli htly-tapered as shown at 16, to allowr 'it to e easily inserted and removed from the tail-stock spindle 6.

It' will be observed Jthat the steel taper 14, has its one end gradually tapering to ,an edge 17 thus forming a pair of fiat faces or conver l 'ng sides 18.

4Havin thus fully described my invention, what I c aim is:

l. A truing device having a cut away top portion to form a resting plate for the fiat ond of a steel taper and a projecting front having a conical opening therein adapted to receive the bent pivot of a balance staff for truino the same.

2. truing device having a cut-away top portion to form a bed or resting plate, and a projecting front provided with a conical opening to receive the pivot of a balance staff. y

3. A truing device havin@- a cut-away 'tap d bed or resting bent pivot of a balance staff to be trued.

4. The combination in a jewelers lathe, oi.i a head-stock, a spindle, and a work holdin, chuck :in said' spindle, of etaitstock hea and a tail-stock fspindle mounted therein, a.. 2in? ti'ung devicehavlng a cut-away top portion to form a bed having a convex upper sufface ancL u project-ing front which is pro- In testimony whereof I have signed my .vided with a conical opening to receive the naine to the specication in the presence of 10 pivot ami shouller of albzlance steif carred two subscribing Witnesses.

by the a 'oi'esai Work io din@ chuck an 1L 5 steel taper adapted to be inserted between DENNIS L DAVIES' the pivot and convex surface of the bed Witnesses: 'formed by said out-away top portion of the J. Gr. RlcnMoND, truing device for trung said pivot. Enw. E. CLARK. 

